"The situation will deteriorate even further," European Council presidentDonald Tusk said, warning of a "new wave of refugees (arriving) from Aleppo andother Syrian regions under Russian bombardment".

"I have no doubt that this challenge has the potential to change theEuropean Union we have built," he told the European Parliament in Strasbourg.

"And what is even more dangerous, it has the potential to create tectonicchanges in the European political landscape. And these are not changes for thebetter."

European Commission president Jean-Claude Juncker meanwhile slammed EUmember states for providing less than half of the guards pledged to the bloc'sFrontex border agency in migrant hotspots Greece and Italy.

"Member states have been moving slowly at a time when they should berunning," he said.

Of the 775 border guards needed, EU countries have only provided 326 overthe past month, Juncker said, adding that many bloc members had also failed sofar to keep their promises of financial support.

The stinging criticism came just days after the EU vowed to help set up100,000 places in reception centres in Greece and along the migrant routethrough the Balkans.

The move is part of a 17-point action plan devised with the countries mostaffected by the crisis.

German Chancellor Angela Merkel and French President Francois Hollande heldtalks on the crisis in Paris on Tuesday, with a French official sayingafterwards the two shared "the same position on what should be done politicallyand on the measures required for the countries on the front line".

Worsening weather

More than half of this year's arrivals in Europe were from Syria, followedby Afghanistan and Iraq, the UN refugee agency said on Tuesday.

Some 562,355 people desperately fleeing war and misery reached Greece'sshores, while around 140,000 arrived in Italy since January.

At least 3,210 people have either died or gone missing while making theperilous journey in flimsy boats.

The flow shows no sign of abating despite the rapid approach of winter,according to the International Organisation for Migration, which reported thearrival of more than 9,000 people in Greece over the weekend.

In Sweden, a group of migrants are locked in a standoff with authorities,saying the village where they have been taken is "too cold" and isolated,officials said on Tuesday.

Around 60 Syrians and Iraqis were taken by bus on Sunday to Limedsforsen,close to the Norwegian border, where they were to stay while their asylumclaims were assessed.

But around a third refused to get off the bus when they saw they were in aforest dozens of kilometres from the nearest town. Many demanded to be taken toa big city – or even to Germany.

As a majority of migrants seek to reach northern Europe, the influx hasoverwhelmed countries along the migrant trail up from Greece through theBalkans, and sparked concern that the EU's cherished "Schengen" system ofborderless travel is under threat.

More than 83,600 people have arrived in Slovenia since mid-October afterHungary shut its Croatian border with a razor-wire fence, police said on Tuesday. — AFP